The Swift Green Filters SGF-W31 Rx pharmaceutical water filter is a compatible replacement for Whirlpool filters, providing fresh, clean, and great tasting drinking water. This high quality filter reduces lead, pharmaceuticals and prescription drugs, herbicides, pesticides, industrial chemicals, metals, minerals and water borne parasites. Additionally, this filter removes chlorine and odors, which are the key elements to great tasting water. Swift Green filters are made with activated carbon that originates from coconut shells, the ultimate source for the worlds best carbon. Combining the carbon with our proprietary technology called EPC results in filters that are superior in performance and contaminant removal. Change filter every 4 to 6 months.